My 91 C4 will not start. When I turn the key on I get nothing. Is this possibly a starter relay issue? I have already tested the battery and all connections, they are goo. What should I look for/check next? Thanks in advance.

 

There are many things it could be so you might start at the battery. How Good is Good? What is the voltage of the battery just sitting normally? When was the cable removed and had it's ends cleaned with a wire brush? You can't always see a corroded connection.

Did you try and move the shifter (if automatic) and make sure the lockout is not doing it. If you are a manual Corvette owner Try pushing the pedal in while cranking.

Is the fuel system pressurizing like normal? You hear the pump run for several seconds before it will crank?

Is there any power evident inside your Corvette? Lights, Dash? What happens when you turn key?

Measure your Battery Voltage and then measure the Fuse Panel voltage. If it is different then there is corrosion in between the Battery and the Fuse panel. The connection that frequently gets nasty is a small post mounted/Isolated on the Frame rail. There is a Red wire about 4 gauge directly from the battery Positive that has a ring terminal to go over the post. The post will likely have several wires attached to it. On my 1988 C4 would do absolutely nothing yet having a good battery and fresh fuel. The battery was normal in the Mid 12 volt range but inside the car on the fuse panel there was roughly 2 volts less than the battery had just read. On the 1988 there are 7 fusible links that ALL get their power here. I removed the nut and the seven fusible links and cleaned with wire brush. Afterwards I reassembled them and everything inside the Corvette suddenly woke up. The radio input voltage was full battery voltage. All the systems like the fuel system primed like usual and the car started instantly.

A place to start if you choose to. There are a lot of folks here at this Forum who are incredibly knowledgeable so you will have an answer soon. Just post as much as you can about your Corvette so we here at the forum know what we are working with.

 

Thanks for the tips. My battery is in the 12 volt range and I have already put new connecters on it. I will try the other voltage measurements you mentioned and check other connections for corrosion (clean them because, as you said you can't always see corrosion). Thanks again, I will post back later.

 

Hello Again, bp308

Is there "any" response out the Corvette when you turn the key? Power at the Fuse panels is the important one, if any of the fuse are blown should be verified while you are at it.

Electrical cleanliness is so important in these Corvette's electrical system. I have an older Corvette as well and it's doesn't need any of the electrical cleaning that the C4 does. Once I saw a loose ground strap, so I reconnected it and my power antenna started working again....

How long have you owned the Corvette? When you have some time it is great to fill out the "Profile" Section. You just tell us what you know about your Corvette, what year, type, transmission, mileage, modifications and any work done recently. The more you give the more "specific" the help you can get.

I found a chemical that really removes the corrosion quickly on electrical components. It is called DeOxIt and is available on Amazon and it works miracles when nothing else could work. I have canned Air and cleaning tools but nothing works like the DeOxIt does.

 

Just finished filling out the profile section. Maybe the additional information will help with diagnosing my problem. Thanks

 

2 terminals on the starter. Big and little. Hook an idiot light to the little and ground it. Try to crank and see if it gets a signal or not. Go from there.

 

If you don't get any juice to the smaller wire when trying to engage the starter and your security light is not on, suspect the starter inhibit relay.

 

I tried cleaning the battery connectors again. this time with DeOxIt and a wire brush. I also checked and my battery has a full charge/ I still get nothing when I turn the key on. No dash lights, don't hear the fuel pump and don/t hear any relays clicking. What do you think?

 

Had a similar problem, Turned out to be broken wire in column for vats.

 

What voltage do you get at the Fuse Panel? You pull a fuse and measure both sides of the fuse holder and one should be "Hot" (12Vdc). If the voltage is lower than the problem is easy to solve. Please let me know what you find there.

So when you turn the key you don't hear the fuel pump prime the system?

Follow Aklim's advice and check the starter motor for power. That is an important test.

If it runs on Ether then the ignition system is working okay. The injectors should all have +12 volts at their connectors when the key is in the "run" position. The ECM supplies them with a ground signal telling the injectors to fire. Check for 12 volts at each injector. Have you tried the NOID Lights yet on the injectors? That just shows the signal from the ECM telling the injectors to fire. Don't be surprised that they fire in groups.

 

I have been on a hiatus for a while and am now back to trying to fix my vette. I replaced the starter switch and somehow managed to disconnect the rod that connects the starter switch to the ignition position selector part of the key assembly (which I also replaced). I think I can fix this if I can figure out how to remove the lower steering column cover. I have the one that the tilt lever and multi-function le3ver come out of, but I can't figure out the lower one. I also replaced the turn signal switych while I had it open. Looking forward to your guidance.

Thanks in advance,
Phil